Azo dyes are really good at helping us detect heavy metal ions in a way. We have made a lot of progress in making Azo dyes in a natural way and using tiny particles, which is called nanotechnology. This has led to the creation of Nano-azo dye products that're easier to use and give faster results. The main points of this review talk about how we can make Nano-azo dyes using things like plant extracts and natural solvents and how we can use techniques like microwaves and sound waves to save energy. Nano-azo dyes are very good at finding metals like iron, copper and lead because they have a big surface area and can be adjusted to work well with light. This is very important. Even though we have gotten some results there are still some problems to solve like making sure the Nano-azo dyes are stable and do not get confused by other ions and finding a way to make them on a big scale so we can use them commercially. We need to make the sensors stronger and find ways to use them with tiny materials and we want to use them to monitor the environment and help people’s health. Using Nano-azo dyes that are made in a way is a great idea for the future because it will help us detect heavy metal ions in a way that is good, for the planet, efficient and affordable.